At a glance
- Client: Australian home automation brand (founder-led, name under NDA)
- Scope: Mobile app, device communication layer, voice assistant integration
- Stack: Flutter, MQTT, cloud backend, Amazon Alexa, Google Assistant
- Hardware supported: 2, 4, 8, 16 and 32-channel relay boards; curtain motor controllers; analog controllers for dimming and fan speed
- Platforms: Android and iOS, from a single Flutter codebase
A founder with the hardware, and no one to build the software
Our client saw a gap in the Australian smart home market: affordable, flexible automation for lights, fans, curtains and appliances. He had a strong business background and had already partnered with an electronics R&D firm to design the hardware.
What he didn't have was a software team. The hardware was ambitious, and without an app that could run every device it supported, there was no product to sell. He brought us in to build that app and the communication layer behind it.
One app, many device types
The R&D team had designed a modular hardware range, not a single device. The app had to support all of it from day one:
- Relay boards in 2, 4, 8, 16 and 32-channel versions, for switching lights and appliances
- Motor controllers for opening and closing curtains
- Analog controllers for dimming bulbs, changing bulb modes and setting fan speeds
- Voice control through Amazon Alexa and Google Assistant
Building a separate screen for each board would have produced five near-identical apps inside one, and every new hardware variant would have meant another release. The software had to treat device types as configuration, not code.
How we built it
A device model driven by configuration
Each board identifies its type and channel count when it is added to a home. The app reads this and builds the controls for it: a 2-channel board gets two switches, a 32-channel board gets thirty-two, grouped by room. Motor and analog controllers get their own control types, such as open, close and stop for curtains and sliders for brightness and fan speed. New hardware variants can be supported without rewriting the app. Learn more about our mobile app development work.
MQTT for real-time control
The app, the server and the hardware talk over MQTT, a lightweight publish-subscribe protocol designed for low-power devices on unreliable networks. A tap in the app publishes a command; the board acts on it and publishes its new state back, so every phone in the home sees the same status in near real time. Commands and state updates are organised by home, room and device, so each phone only receives updates for the homes it belongs to.
Simple device onboarding
Adding a new board is a guided setup inside the app. The app finds the new board, passes it the home's Wi-Fi details, and asks the homeowner which room it belongs to. From then on, the board appears in the app with the right controls for its type.
Voice control with Alexa and Google Home
We connected the system to Amazon Alexa and Google Assistant, so users can say "turn off the living room lights" or "close the bedroom curtains". Homeowners link their account to Alexa or Google Home once, and the devices and rooms they set up in the app become available to the assistant.
Reliability and security
If the connection drops, the app shows each device's last known state and picks up live updates again as soon as the connection returns. Communication between the app, the server and the devices is encrypted, and each device connects with its own credentials, so one home's devices cannot be controlled from another.
The architecture
The app never talks to a board directly; every command and every state update passes through the MQTT broker. Voice commands from Alexa and Google Home enter the same path through the server, so a switch flipped by voice shows up in the app instantly.
Results
The client launched his product range in Australia with a single app that runs every device in the line-up.
- Seven device types controlled from one app: five relay board sizes, curtain motors and analog controllers
- One Flutter codebase for both Android and iOS
- Voice control through both Amazon Alexa and Google Assistant
- New hardware variants added through configuration, not an app rewrite
What this means for your connected product
If you have hardware, or a hardware partner, and need the app and cloud layer that make it a product, this is the work we do. We build mobile apps that handle many device types, real-time control over MQTT, and voice assistant integration, and we work alongside your electronics team rather than around them.
